Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces JB/T 2300-2011 Slewing bearings; the following technical changes have been made with respect to JB/T 2300-2011:
——the content of Table 7 is modified (see Table 7; Table 7 in Edition 2011).
——the content of Table 8 is modified (see Table 8; Table 8 in Edition 2011).
——the content of assembly is modified (see 5.2; 5.2 in Edition 2011).
——the content of testing methods is modified (see Clause 6; Clause 6 in Edition 2011);
——the content of inspection rules is modified (see Clause 7; Clause 7 in Edition 2011);
——the content of the load-bearing capacity graph is modified (see B.2; B.2 in Edition 2011);
——the durability test method is added (see B.3);
This standard was proposed by the China Machinery Industry Federation.
This standard is under the jurisdiction of SAC/TC 334 National Technical Committee on Earth-moving Machine of Standardization Administration of China.
The previous editions of this standard are as follows:
——JB 2300-1978, JB/T 2300-1984, JB/T 2300-1999 and JB/T 2300-2011.
Slewing bearing
1 Scope
This standard specifies the symbols, classification and designation, requirements, testing methods, inspection rules, marking, packaging, transportation and storage of slewing bearings.
This standard is applicable to slewing bearings for engineering machinery, mining machinery, port machinery, construction machinery and other machinery requiring relative slewing movement of two parts.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 308.1 Rolling bearings - Balls - Part 1: Steel balls
GB/T 699 Quality carbon structure steels
GB/T 1357 Cylindrical gears for general engineering and for heavy engineering - Modules
GB/T 3077 Alloy structure steels
GB/T 4661 Rolling bearings - Cylindrical rollers
GB/T 5617 Determination of effective depth of hardening after induction or flame hardening of steel
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 10095.1-2008 Cylindrical gears - System of accuracy - Part 1: Definitions and allowable values of deviations relevant to corresponding flanks of gear teeth
GB/T 10095.2-2008 Cylindrical gears - System of accuracy - Part 2: Definitions and allowable values of deviations relevant to radial composite deviations and runout information
GB/Z 18620.1 Cylindrical gears - Code of inspection practice - Part 1: Inspection of corresponding flanks of gear teeth
GB/Z 18620.2 Cylindrical gears - Code of inspection practice - Part 2: Inspection related to radial composite deviations, runout, tooth thickness and backlash
HG/T 2349 Polyamide 1010 resin
HG/T 2811 Rubber material of rotary shaft lip seal ring
JB/T 5947 Engineering machinery - General technical specifications for packaging
JB/T 7940.7 Grease nipples and lubricating cups - Technical specification
3 Symbols
See Table 1 and Figure 1 for the appellation and symbol of each part of a slewing bearing.
Table 1 Appellation and symbol of each part
Symbol Appellation Symbol Appellation
DL Diameter of center circle of roller path (of upper row) d1 Inner diameter of outer ring
DW Diameter of rolling element (of upper row) D3 Inner diameter of inner ring
D1 Distribution diameter for mounting holes of outer ring H Total height
D2 Distribution diameter for mounting holes of inner ring H1 Height of inner/outer ring
D Nominal outer diameter h Height difference between two end faces of inner and outer rings
d Nominal inner diameter DS Effective case depth
n Number of mounting holes L Thread length of mounting threaded hole
n1 Number of lubricating holes da Diameter of addendum circle
dn1 Diameter of mounting unthreaded hole of outer ring m Module
dn2 Diameter of mounting unthreaded hole of inner ring x Radial modification coefficient of gear
dm1 Diameter of mounting threaded hole of outer ring z Number of teeth
dm2 Diameter of mounting thread hole of inner ring b Width of tooth
Note: The outer ring in Figure a) is composed of an upper ring and a lower ring; the inner ring in Figure b) is composed of an upper ring and a lower ring.
Figure 1 Appellation and symbol of each part of a slewing bearing (taking a triple-row roller slewing bearing as an example)
4 Classification and designation
4.1 Type
4.1.1 Structural style
A slewing bearing is composed of rings (inner ring, outer ring and upper/lower ring), rolling elements, separators, sealing tapes, grease nipples/lubricating cups, etc., which are classified into four series by structural type:
a) single-row four-point contact ball slewing bearings (series 01), as shown in Figure 2;
b) double-row different-diameter ball slewing bearings (series 02), as shown in Figure 3, with the nominal diameter combination of rolling elements (of upper/lower row) as follows: 25/20, 30/25, 40/30, 50/40, 60/50;
c) single-row crossed roller slewing bearings (series 11), as shown in Figure 4, whose rolling elements are 1:1 cross arranged at 90°;
d) triple-row roller slewing bearings (series 13), as shown in Figure 5, whose nominal diameter combination of rolling elements is 25/20/16, 32/25/20, 40/32/25, 45/32/25 and 50/40/25.
Note: The mounting holes of inner and outer rings may be classified into unthreaded holes or threaded holes (this note also applies to Figures 3~5, the type of threaded holes is the same as that in Figure 2, with designation of DW omitted).
Figure 2 Single row four-point contact ball slewing bearings (series 01)
Figure 3 Double-row different-diameter ball slewing bearings (series 02)
Figure 4 Single-row crossed roller slewing bearings (series 11)
Figure 5 Triple-row roller slewing bearings (series 13)
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4.1.2 Transmission types
Transmission types are classified into:
a) 0——toothless type;
b) 1——external teeth of involute cylindrical gear with a smaller meshing module;
c) 2——external teeth of involute cylindrical gear with a greater meshing module;
d) 3——internal teeth of involute cylindrical gear with a smaller meshing module;
e) 4——internal teeth of involute cylindrical gear with a greater meshing module.
4.1.3 Mounting fitting types
Mounting fitting types are classified into:
a) 0——standard type with no seam allowance;
b) 1——standard type with a seam allowance;
c) 2——special type.
4.1.4 Mounting hole types
Mounting hole types are classified into:
a) 0——both the mounting holes of inner and outer ring are unthreaded holes;
b) 1——both the mounting holes of inner and outer ring are threaded holes;
c) 2——the mounting holes of inner ring are threaded holes, and those of outer ring are unthreaded holes;
d) 3——the mounting holes of outer ring are threaded holes, and those of inner ring are unthreaded holes.
4.2 Basic parameters
4.2.1 See Table 2 for the basic parameters of single-row four-point contact ball slewing bearings.
Contents
Foreword V
1 Scope
2 Normative references
3 Symbols
4 Classification and designation
4.1 Type
4.2 Basic parameters
4.3 Marking
5 Requirements
5.1 Parts
5.2 Assembly
5.3 Selection calculation
5.4 Load-bearing capacity curve
5.5 Other requirements
6 Testing methods
6.1 Testing of parts
6.2 Measurement of assembly precision
7 Inspection rules
7.1 End-of-manufacturing inspection
7.2 Type inspection
7.3 Judgment rules
7.4 Other requirements
8 Marking, packaging, transportation and storage
8.1 Marking
8.2 Packaging
8.3 Transportation and storage
Annex A (Informative) Calculation method of slewing bearing selection
A.1 Overview
A.2 Calculation for selection of single-row four-point contact ball slewing bearings
A.3 Calculation for selection of double-row different-diameter ball type slewing bearings
A.4 Calculation for selection of single-row crossed roller slewing bearings
A.5 Calculation for selection of triple-row roller slewing bearings (total radial force Fr is borne by radial rolling elements)
A.6 Strength check of mounting bolts
Annex B (Informative) Load-bearing capacity curve of slewing bearing
B.1 Application conditions
B.2 Load-bearing capacity curve
B.3 Durability test method
Bibliography
